The purpose of the present study is to evaluate among healthy human subjects (N=100) effects of plant stanol esters (3 grams/day for 6 months) as part of daily diet in margarine on arterial endothelial cells, arterial stiffness, autonomic innervation of the arteries, arterial blood flow and serum fats. The non-invasive arterial measurements (VaSera®, EndoPat® and WinCRPS®) are performed and blood samples are taken at the beginning and at the end of the 6-month-long study period. Also questionnaires concerning healthy, and life and dietary habits are fulfilled. Dietary records (twice for a 3-day-period) are done.